Bruce E. Cutter

Fire Frequency on an Oak-Hickory Ridgetop in the Missouri Ozarks

-Wedges taken from 24 post oaks (Quercus stellata Wang.) growing on a ridge in an oak-hickory stand were used to reconstruct the fire history in the Houston Ranger District in Missouris Mark Twain National Forest. A chronology was constructed dating from 1734 to 1991. Fire frequency was greatest between 1740 and 1850 with a mean return interval of 2.8 yr. After 1850, the fire return interval increased to 24 yr. This change in fire return regimes is coincident with settlement of the area by Anglo-Americans.

A dendrochronological study of black and scarlet oak decline in the Missouri Ozarks

Abstract Examination of tree-ring data revealed important relationships regarding red oak decline in the Missouri Ozarks. Red oaks, mainly black and scarlet oak, exhibiting greater than 30% crown dieback had significantly lower present-day growth rates compared with trees with less than 30% dieback. Red oaks with declining crowns first showed significantly lower radial growth than trees that are healthy at present in the 10 years following years of severe drought in southeastern Missouri. These dates for initiation of radial growth decline varied by tree age, and were 1936 for 60–79-year-old trees and 1952 for 40–59-year-old trees.

Barium and manganese trends in tree-rings as monitors of sulfur deposition

Barium and manganese concentrations in radial growth increments of heartwood from Juniperus virginiana L. are used to examine changes in soil reaction and sulfur deposition. Barium and Mn trends from trees growing on 2 sites with acid, low-Ca soils, signaled sulfur-induced changes in soil acidity after 1870, while Ba and Mn trends before 1870 did not. Factors controlling Ba availability are hypothesized to have changed from soil acidity before 1870 to precipitation of BaSO4 by increased soil sulfate after 1870.

Thinning effects on diameter growth in black and scarlet oak as shown by tree ring analyses

Abstract In the period 1953–1954, five levels of thinning were imposed as part of a crop tree release study on a 32-year-old mixed stand of scarlet oak ( Quercus coccinea Muench.) and black oak ( Quercus velutina Lam.) located in southeastern Missouri. In winter 1985, 162 live trees were felled (90 scarlet oaks and 72 black oaks). A section of 10 cm thickness was cut from the base of each butt log. Dendrochronological techniques were used to gather and prepare data to compare treatment responses. Although there was a significant differential treatment response attributable to thinning, the timing of this response varied between the two species. Black oaks had a 10 year period of increased differential growth immediately after the thinning whereas the scarlet oaks, with a 12 year differential growth period, lagged 6–7 years behind. This was not apparent using the standard inventory techniques of periodic diameter measurements.

mRx: Negotiating collaborative decisions

In this paper, we present the architecture for a working prototype of a decision tool, the mRx. The goal of this prototype was to develop a simple, yet valid, tool to help members of the forestry community to collaboratively negotiate decisions for prescribed burns. The architecture of the mRx has been designed by mapping key learning strategies to pedagogical models. Technological affordances are then leveraged to support these strategies and models.

mRx: A CSCL Decision-Making Environment

In this paper, we present the architecture of an online collaborative decision making learning environment, the mRx. The goal of this prototype is to present a simple; yet, reasoned and systematic, tool to help members of the natural resources community to collaboratively negotiate decisions for prescribed burns. The architecture of the mRx has been designed by mapping key learning strategies to technological affordances that support these strategies. Initial user testing indicates that learners and professionals find the tool useful in gaining insights into different perspectives and, thereby, creating a more reasoned and inclusive decision to burn.